Home |
Search |
Today's Posts |
#1
![]() |
|||
|
|||
![]()
I'm preparing an article for a local radio club magazine about the nature of
radio and electromagnetic radiation in general. While this is a non mathematical and general descriptive treatment of the subject it is a challenge to make it clear and consistent. I know this group has some expertise on this subject and would appreciate any constructive comment and suggestions regarding the attached article. http://members.optushome.com.au/vk6ysf/vk6ysf/radio.htm Thank you for your time. Regards Peter VK6YSF |
#2
![]() |
|||
|
|||
![]()
On Apr 30, 4:14*am, "Peter" wrote:
I know this group has some expertise on this subject and would appreciate any constructive comment and suggestions regarding the attached article. The two-dimensional Fig. 2-2 graph is confusing in that it could be inferred that the E and H fields are 90 degrees out of phase in time and are never zero at the same time. The E and H fields are in phase in time as demonstrated by Fig. 2-4. -- 73, Cecil, w5dxp.com |
#3
![]() |
|||
|
|||
![]()
On Fri, 30 Apr 2010 05:12:38 -0700 (PDT), Cecil Moore
wrote: On Apr 30, 4:14*am, "Peter" wrote: I know this group has some expertise on this subject and would appreciate any constructive comment and suggestions regarding the attached article. The two-dimensional Fig. 2-2 graph is confusing in that it could be inferred that the E and H fields are 90 degrees out of phase in time and are never zero at the same time. The E and H fields are in phase in time as demonstrated by Fig. 2-4. Hmmm. I'm no expert, but I thought they were 90 degrees out of phase. It's the rapidly changing H field that creates the E field and vica versa. If you look closely, Fig 2-4 also shows them 90 degrees out of phase. To the OP, heat is not electromagnetic radiation. Light and x-rays are. You can heat something by pointing em radiation at it and something that is hot gives off infra-red em radiation, but heat itself is not em radiation. Pat |
#4
![]() |
|||
|
|||
![]()
On Apr 30, 9:00*am, wrote:
On Fri, 30 Apr 2010 05:12:38 -0700 (PDT), Cecil Moore wrote: On Apr 30, 4:14*am, "Peter" wrote: I know this group has some expertise on this subject and would appreciate any constructive comment and suggestions regarding the attached article. The two-dimensional Fig. 2-2 graph is confusing in that it could be inferred that the E and H fields are 90 degrees out of phase in time and are never zero at the same time. The E and H fields are in phase in time as demonstrated by Fig. 2-4. Hmmm. *I'm no expert, but I thought they were 90 degrees out of phase. It's the rapidly changing H field that creates the E field and vica versa. *If you look closely, Fig 2-4 also shows them 90 degrees out of phase. To the OP, heat is not electromagnetic radiation. *Light and x-rays are. *You can heat something by pointing em radiation at it and something that is hot gives off infra-red em radiation, but heat itself is not em radiation. * Pat It is accepted that radiation is "an acceleration that generates or transfers a charge ". This is an empty statement if one cannot explain the mechanics of the operation.Certainly you have to determine what you have in hand to provide this action, and at the present time there is no agreement whether it is a wave flow of a constituent, what ever that may be, or a particle. Therefore one has to determine exactly what we are going to accelerate and how we are going to avoid the effects of gravity since radiation does not follow the action of a descending lob. This as yet has not been determined, so we cannot begin to understand! For me I see a wave as being an adjective and a particle as a noun. But a word of warning,physicists do not follow the same rules of the general public, so if you have a day or two to spare get a physicist to explain exactly what a 'wave' is and how does it fit with the required straight line accelerating trajectory that opposes gravity! You just cannot explain "radio" until you determine what you are accelerating and how. Sorry about that Regards Art |
#5
![]() |
|||
|
|||
![]()
On Fri, 30 Apr 2010 17:14:28 +0800, "Peter" wrote:
While this is a non mathematical and general descriptive treatment of the subject it is a challenge to make it clear and consistent. Hi Peter, Yes, your treatment does tend to veer towards the exotic topics. Stick to the basics. You have a wonderful resource that you point to in the Navy training manuals. As a former instructor for the Navy's Electronic Technician A and C schools, I can attest this material manages the balance between technical and theoretical. You may notice that the first manual introduces the concept of photons, but no where goes into "duality." And for good reason, it doesn't matter one whit. When you raise this concept, the weaker participants of your audience would then think about solar particles in competition with solar radiation (light, largely). They would probably miss the vast difference in propagation speed. Solar radiation, of course, travels at the speed of light. This is why it is called radiation. Solar particles (the erroneous dual to the photon) travels at less than 1% of the speed of light. If any of your audience were to simply consider their final's tubes, within that glass enclosure, electrons travel at 90% of the speed of light. Dribble a little air into that vacuum tube, and the speed of any electron would plummet to inches per hour. So, what value is there in opening that can of worms? 73's Richard Clark, KB7QHC |
#6
![]() |
|||
|
|||
![]()
On Apr 30, 12:59*pm, Richard Clark wrote:
On Fri, 30 Apr 2010 17:14:28 +0800, "Peter" wrote: While this is a non mathematical and general descriptive treatment of the subject it is a challenge to make it clear and consistent. Hi Peter, Yes, your treatment does tend to veer towards the exotic topics. Stick to the basics. *You have a wonderful resource that you point to in the Navy training manuals. *As a former instructor for the Navy's Electronic Technician A and C schools, I can attest this material manages the balance between technical and theoretical. You may notice that the first manual introduces the concept of photons, but no where goes into "duality." *And for good reason, it doesn't matter one whit. *When you raise this concept, the weaker participants of your audience would then think about solar particles in competition with solar radiation (light, largely). *They would probably miss the vast difference in propagation speed. Solar radiation, of course, travels at the speed of light. *This is why it is called radiation. *Solar particles (the erroneous dual to the photon) travels at less than 1% of the speed of light. *If any of your audience were to simply consider their final's tubes, within that glass enclosure, electrons travel at 90% of the speed of light. Dribble a little air into that vacuum tube, and the speed of any electron would plummet to inches per hour. So, what value is there in opening that can of worms? 73's Richard Clark, KB7QHC Obviously a problem here! Quantum mechanics states radio rotates around particles and classical physics revolves about waves. If radiation is an acceleration of charge then it is pivotable that one decides what is being accelerated in the first place! If Einstein is correct that the speed of light is not to be exceeded then one has to decide whether a wave is lighter than the smallest particle possible. Waves do have length a physicist would say where as a particle can be a point! How we get straight line trajectory while gravity is present is easily solved. Pysicists have now removed gravity from the Standard Model to get over that problem.The Navy on the other hand ignores the duallity question. |
#7
![]() |
|||
|
|||
![]() |
#8
![]() |
|||
|
|||
![]()
Roy Lewallen wrote in
: The time phase angle between E and H is determined by the medium the wave is propagating through. The (complex) ratio of E to H is called the intrinsic impedance of the medium, and for lossless media, it's always a purely real number (about 377 ohms for air or free space), meaning that E and H are in phase. Only when propagating through a lossy medium are E and H not in time phase, and then the maximum phase difference is always less than 45 degrees. If I understand this correctly, a field arrangement with E and H in time and space quadrature is not propagating energy, but rather energy exchange. In very close to an antenna, the time phase relationship of E and H may be close to quadrature due to the inductive or reactive field close to the conductors, but that changes eventually to 'in-phase' in the far radiation field in free space (as the induction field components decay more quickly with distance than the radiation field components). If that is the case, the complex value of E/H varies from very close to the far field. I have seen plots of E/H vs distance that treated E/H as a real number, but I suspect that it is more complex when all of the components of E and H are included. Thoughts? Owen |
#9
![]() |
|||
|
|||
![]()
On Apr 30, 5:05*pm, Owen Duffy wrote:
Roy Lewallen wrote om: The time phase angle between E and H is determined by the medium the wave is propagating through. The (complex) ratio of E to H is called the intrinsic impedance of the medium, and for lossless media, it's always a purely real number (about 377 ohms for air or free space), meaning that E and H are in phase. Only when propagating through a lossy medium are E and H not in time phase, and then the maximum phase difference is always less than 45 degrees. If I understand this correctly, a field arrangement with E and H in time and space quadrature is not propagating energy, but rather energy exchange. In very close to an antenna, the time phase relationship of E and H may be close to quadrature due to the inductive or reactive field close to the conductors, but that changes eventually to 'in-phase' in the far radiation field in free space (as the induction field components decay more quickly with distance than the radiation field components). If that is the case, the complex value of E/H varies from very close to the far field. I have seen plots of E/H vs distance that treated E/H as a real number, but I suspect that it is more complex when all of the components of E and H are included. Thoughts? Owen Owen By observation the E and H fields can be seen as a tank circuit where all vectors are accounted for so that one follows the notion that energy cannot be created or destroyed plus the other laws of Newton. When we stray from that scenario we get into new theories or imaginations The moment we stray from boundary laws one is coersed into thinking like somebody of a lesser nature than past masters who determine phenomina from observation that is matched by known principles. How on earth can we relate to near fields and far fields if we haven't decided what the media concists of. My approach was to stick with the laws of Maxwell which dictates static and dynamic fields where all forces are accounted for, which shows that gravity can only be negated by the use of Newton's laws. Thus my foundations were not built on a layer of sand but what is accepted via Maxwell's laws. In other words, the laws of Maxwell points to the presence of particles when dealing with fields and displacements by virtue of the units used. There are lots of things that exhibit properties of other materials and thus by observation can be compared to other things in action, but they should never be considered as one and the same unless they are matched in their entirety. Particles and waves have lurched beyond science by considering them to be one and the same purely by action and not by substance. If one is going to discuss energy exchange as with inductance and capacitance to determine relative phase angles , fields etc one cannot stray from the tank circuit observations. Regards Art |
#10
![]() |
|||
|
|||
![]() It is accepted that radiation is "an acceleration that generates or transfers a charge ". This is an empty statement if one cannot explain the mechanics of the operation.Certainly you have to determine what you have in hand to provide this action, and at the present time there is no agreement whether it is a wave flow of a constituent, what ever that may be, or a particle. Therefore one has to determine exactly what we are going to accelerate and how we are going to avoid the effects of gravity since radiation does not follow the action of a descending lob. This as yet has not been determined, so we cannot begin to understand! For me I see a wave as being an adjective and a particle as a noun. But a word of warning,physicists do not follow the same rules of the general public, so if you have a day or two to spare get a physicist to explain exactly what a 'wave' is and how does it fit with the required straight line accelerating trajectory that opposes gravity! You just cannot explain "radio" until you determine what you are accelerating and how. Sorry about that Regards Art You are really good, Art. How do you keep it up? You make new and fresh nonsense up with very many of your posts. Not every one, but you do have to carry on your themes after all. Still, it's quite an effort you put into it. How do you continue to make almost no sense? That's really tough. I mean, even random chance would say you occasionally have to be realistic. tom K0TAR |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|